Digital Radiographic imaging is used to generate digital projection X-ray images of subjects, typically human patients. Common technologies in the art are Computed Radiography (CR) and Digital Radiography (DR). CR uses stimulable phosphor sheets that capture and absorb the X ray energy, store it and then the phosphor sheets are being scanned to provide the digital image. In DR, the radiation strikes a plate onto which large area position sensitive detectors are generating a digital image in real time.
The imaged subjects have internal structures that differ in X ray absorption due to different thickness, density and atomic composition. The internal structures may have different response to different X ray energy range, thus allowing to enhance the contrast between certain structures by different choice of beam energy. In dual energy scanning techniques, two images are obtained at two different beam energy ranges and a third improved image is usually generated by normalization and/or another mathematical manipulation such as subtraction technique, as an example. This technique had been used for the last two decades. The improvement may be directed to elimination of certain structures (e.g. bones in soft tissue imaging), differentiating between structures (e.g. bone from contrast agent, explosive from other materials) or enhancing the contrast between neighboring structures (e.g. tissues in a patient).
The existing methods such as multislice CT are relatively excessive radiation-prone and there is a need to reduce the amount of radiation that is used during patient imaging. In dual energy subtraction, acquisition of two images offers less radiation.
The ability to convert computed radiography combined with digital radiography, each having its unique features to dual energy system while maintaining relatively low doses of radiation opens the opportunity to many potential medical applications.